Mobile stations, such as cell phones, are sometimes used to communicate with emergency call services, such as Public Safety Answering Points (PSAPs) via a 911 call. Some callers, however, may be unable or unwilling to communicate verbally with the emergency call service. Such callers, for example, may be disabled and unable to speak. Other callers may be subject to conditions which may make speaking unsafe, such as being in the midst of a kidnapping or a robbery. Other users may not have enough time to deal with the delays which sometimes occur when placing a voice call to 911, such as delays caused by network congestion, dropped calls, and/or having to wait for a 911 operator. Still other users may be timid about the prospect of their voice call being recorded by 911, such as bystanders who might otherwise summon help. Still other users may be hearing-impaired and have difficulty or be unable to verbally communicate.
Modern portable phones include features such as text messaging, e-mail, instant messages, and video chat, which are quite widely used, in many cases, instead of voice calls. These features also provide effective and popular ways for the hearing/speaking-impaired to communicate with others. However, during emergencies, these wireless devices do not always provide adequate access to the emergency 911 system.
The current 911 emergency call system for the hearing-impaired generally requires the use of a teletype (TTY) text telephone device to contact 911 in an emergency. TTY devices are relatively large and bulky—typically the size of a laptop computer. Due to the form factor, it is understandable that TTY devices are less desirable than a portable phone. Moreover, it is unlikely that a hearing impaired user would carry multiple mini-QWERTY style devices in anticipation of an emergency.
Although the relatively few existing IP-capable 911 Public Safety Answering Points (PSAPs) have the capability to accept text-based communications, the only carrier-supported offering is through the use of 5 digit SMS short codes which may lack important features, such as information about the location of the call.